1. Technical Field
In retractable awnings and, more particularly, motor-driven retractable awnings, spring-biased support arms for the awning bias the awning toward an extended position. Reversible motor drives for the awnings permit the spring-bias support arms to extend the awnings, or, when the motor is driven in an opposite direction, retract the awnings against the bias of the support arms. As disclosed herein, in the event the motor drive becomes inoperable, a manual override permits the awnings to be retracted with, for example, a ratchet wrench.
2. Description of the Relevant Art
Awnings for covering windows, doorways, or the like, have been in common use for many years with most awnings being of the hand-cranked type so they can be extended or retracted manually with the use of a crank handle. More recently, motor-driven awnings have become desirable wherein a reversible motor extends or retracts the awning as desired. One problem with motor-driven awnings resides in the fact that motors sometimes become inoperable while the awning is extended, and it is therefore necessary to leave the awning extended until the motor can be fixed. This becomes a particular problem when the awning is mounted on the side of a recreational vehicle or the like inasmuch as the vehicle cannot be operated when the awning is extended thereby immobilizing the vehicle and its operator. Further, if the awning is extended and cannot be furled, the awning or components thereof could suffer significant damage due to severe wind or other inclement weather conditions.
Some prior designs have attempted to address this concern by using a planetary gear system between the motor output and a shaft driving the awning. A planetary gear generally has three points of rotation about a common axis, one point corresponding to a center sun gear, one point corresponding to an outer ring gear, and one point corresponding to the rotation of an intermediate planetary carrier with multiple pinion gears that have individual offset axes as well. In operation, one of the points is generally restrained to create the desired drive output ratio. In the planetary gear configuration used for the awning applications, the motor is attached to a first point of rotation, the manual crank is attached to a second point of rotation, and the output shaft is attached to a third point of rotation. Therefore, if the manual crank is rotated, the motor is not and is therefore the fixed point. Likewise, if the motor is rotated, then the manual crank is not and is therefore the fixed point. Incorporation of a planetary gear system into an awning control adds cost and weight to the awning in the form of the planetary gear set, a manual crank gearbox, and a manual crank handle to operate the awning manually. It also increases the length of the awning box without increasing the canopy coverage. Powered awning models with the planetary gear system are not popular currently due to the cost and weight penalty of the current designs.
The information included in this Background section of the specification, including any references cited herein and any description or discussion thereof, is included for technical reference purposes only and is not to be regarded subject matter by which the scope of the invention is to be bound.